[0001] The invention relates to an assembly of a headlight and a connector, in which
- the headlight comprises:
. an electric discharge lamp provided with a lamp cap and electrical conductors,
which extend from the lamp to contacts at the lamp cap,
. a reflector provided with an opening for receiving the lamp cap of the lamp
and with fixing means arranged to surround this opening,
. a fixing member for fixing the lamp cap in the opening of the reflector, which
fixing member is adapted to cooperate with the fixing means of the reflector, and
- the connector has main contacts for connecting the discharge lamp to a lamp circuit
when the main contacts of the connector are arranged against the contacts at the lamp
cap.
A headlight for such an assembly is known from EP 152649 A1 (PHN 10 907).
[0002] The electric discharge lamp used in the headlight lamp requires a high voltage of
several kV to ignite and to produce rapidly a considerable quantity of light. It is
dangerous when bare metal parts of the lamp are touched when they are applied to this
high voltage. These parts could be touched if the lamp is connected
via the connector to its voltage source before the lamp is arranged in the reflector.
It may also be dangerous when the connector is applied to a high voltage, while it
is detached from the contacts at the lamp cap, for example when the lamp is exchanged.
[0003] The invention has for its object to provide an assembly of the kind described in
the opening paragraph, in which the risk of touching alive bare metal parts is obviated.
[0004] According to the invention, this object is achieved in said assembly in that the
connector has additional contacts adapted to be included in a low-voltage circuit
feeding the lamp circuit and the headlight has beside the lamp cap a contact member
which electrically interconnects the additional contacts of the connector when the
main contacts of the connector are arranged against the contacts at the lamp cap.
[0005] In the assembly according to the invention, the reflector or the fixing member can
have a contact member which closes, in a vehicle, when the connector is arranged,
an electrical circuit of low voltage, for example 12 V, as a result of which the lamp
circuit of high voltage, for example 10 kV, is excited. Another possibility consists
in that the reflector and the fixing member each have a complementary part of this
contact member. When the connector is detached from the headlight, the current supply
to the feeding apparatus of the headlight is therefore interrupted.
[0006] From a view point of construction, a contact member at the reflector or at the fixing
member is to be preferred. Of these two possibilities, that of providing a contact
member at the fixing member is easiest to realize.
[0007] In the assembly according to the invention, it is not possible to supply the discharge
lamp outside the reflector with a high voltage by placing the connector on the contacts
of the lamp cap if the additional contacts are not intentionally interconnected by
artificial means. The possibility of touching accidentally a bare conductor carrying
high voltage,
i.e. either a conductor of the discharge lamp or a main contact of the connector, is thus
effectively obviated.
[0008] The additional contacts of the connector can form part of a switch which is closed
by the contact member. The contact member can then itself be an electrical isolator.
[0009] In an attractive embodiment, however, the additional contacts are electrically interconnected
by an electrically conducting contact member. The contact member is then electrically
included in the circuit of which these additional contacts form part. The additional
contacts may be arranged, for example, opposite to each other in the proximity one
of the other so that they may be interconnected, for example, by one strip, pin or
sleeve. Another possibility consists in that they are arranged at a greater relative
distance so as to be spatially separated and each come into contact with their own,
for example strip-, pin- or sleeve-shaped contact part of the contact member. Since
a loose connector may carry a low voltage, the additional contacts are preferably
arranged so as to be sunk into the connector, in the embodiment last described, for
example in an individual cavity.
[0010] The assembly can be used in vehicles. The headlight of the assembly can be suitable
for producing a high beam or a dipped beam or for use as a fog-lamp. The electric
discharge lamp used may then be, for example, a high-pressure sodium discharge lamp
or a high-pressure mercury discharge lamp with metal halide additions or a high-pressure
xenon discharge lamp, as the case may be with halide additions.
[0011] The contacts at the lamp cap and the contact member may extend in the longitudinal
direction of the reflector, as it is shown in the drawings, or in a direction cross
thereto. In the last event less space longitudinally of the reflector is needed by
the connector.
[0012] Embodiments of the assembly according to the invention are shown in the drawings.
In the drawings:
Figure 1 is a longitudinal sectional view of a first embodiment of an assembly,
Figure 2 is a front elevation of a connector for a second embodiment in an electric
circuit,
Figure 3 is a side elevation of the second embodiment of an assembly, in which the
connector is shown partly broken away and partly in longitudinal sectional view.
[0013] In Figure 1, the assembly of headlight and connector comprises a headlight 1 and
a connector 2.
[0014] The headlight 1 comprises an electric discharge lamp 3 provided with a lamp cap 4
and electrical conductors 5, which extend from the lamp 3 to contacts 6 at the lamp
cap 4.
[0015] The headlight 1 further comprises a reflector 7 provided with an opening 8 for receiving
the lamp cap 4 of the lamp 3 and with fixing means 9 around this opening 8. The fixing
means 9 are an integral part of the reflector 7 in the embodiment shown.
[0016] The headlight further comprises a fixing member 10 for fixing the lamp cap 4 in the
opening 8 of the reflector 7. The fixing member 10 is adapted to cooperate with the
fixing means 9 of the reflector 7. In the embodiment shown, the fixing member is a
union nut which is arranged axially around the fixing means 9 and the lamp cap 4 and
is then rotated through an angle of several degrees to an abutment stop to cooperate
with the fixing means 9.
[0017] The connector 2 has main contacts 11 for connection of the discharge lamp 3 to a
lamp circuit when the main contacts 11 of the connector 2 are arranged against the
contacts 6 at the lamp cap 4.
[0018] The connector 2 has additional contacts 12 adapted to be included in a low-voltage
circuit feeding the lamp circuit. The headlight 1 has beside the lamp cap 4 a contact
member 13, which electrically interconnects the additional contacts 12 of the connector
2 when the main contacts 11 of the connector 2 are arranged against the contacts 6
of the lamp cap 4.
[0019] In the embodiments shown, the contact member 13 comprises two contact parts 14 in
the form of metal strips, which are interconnected by means of a metal annular disk
15. The contact member 13 is therefore electrically conducting and is electrically
included in the circuit through the additional contacts 12. The contact member 13
has an individual contact part 14 for each additional contact 12 of the connector
2. The contact member 13 is present in the fixing member 10.
[0020] When the assembly 1 is mounted, the electrical discharge lamp 3 is introduced through
the opening 8 inside the reflector 7 so that the opening 8 receives the lamp cap 4.
The fixing member 10 is then provided, this member first performing a translation
to the reflector 7 and the lamp cap 4 and then a rotation, cams 16 then engaging behind
the fixing means 9. It is not until then that the contacts 6 at the lamp cap 4 and
the contact strips 14 of the contact member 13 in the fixing member 10 are in a configuration
corresponding to the configuration of the main contacts 11 and the additional contacts
12 of the connector 2.
[0021] When the connector 2 is placed on the headlight 1, the contacts 6 at the lamp cap
4 are simultaneously connected to a lamp circuit and the additional contacts 12 of
the connector 2 are interconnected so that a low-voltage circuit is closed which feeds
the lamp circuit. When the contact member 13 does not engage into the connector 2,
the main contacts 11 and hence the discharge lamp 3 do not carry a high voltage.
[0022] An attractive property of the assembly shown is that an electric switch with movable
parts is present neither in the connector 2 nor at the headlight 1. A small elastic
deformation of the main contacts 11 and the additional contacts 12 when they are in
contact with the contacts 6 and with the contact member 13, respectively, is left
out of consideration here.
[0023] It is also favourable that the additional contacts 12 are arranged in an individual
cavity 17 in the connector 2 so as to be spatially separated from each other. Washers
are designated by reference numeral 18.
[0024] Figure 2 shows a connector 22 in front elevation, as well as a voltage source 19
and a high-voltage supply apparatus 20. The high-voltage supply apparatus 20 is included
together with the voltage source 19 in a low-voltage circuit 39, which is opened due
to the fact that additional contacts 32 of the connector 22 are not interconnected.
It is not until the additional contacts 32 are interconnected by means of a contact
member 33 (Figure 3) that the high-voltage supply apparatus 20 is excited and a high
voltage is applied across the main contacts 31 of the connector 22 which are included
together with the lamp 3 in a lamp circuit 40.
[0025] It appears from Figure 3 that the additional contacts 32 are interconnected by means
of the contact member 33, which is present at the reflector 27, at the instant at
which the connector 22 is placed on the lamp cap 24. The contact member 33 is then
connected electrically in series with the additional contacts 32, just like the contact
member 13 with the additional contacts 12 in Figure 1. The lamp cap 24 has a contact
26 and is held in the reflector 27 by a fixing member 30. The lamp cap 24, the reflector
27 and the fixing member 30 form part of a headlight 21.
1. An assembly of a headlight and a connector, in which
- the headlight comprises:
. an electric discharge lamp provided with a lamp cap and electrical conductors,
which extend from the lamp to contacts at the lamp cap,
. a reflector provided with an opening for receiving the lamp cap of the lamp
and with fixing means arranged to surround this opening,
. a fixing member for fixing the lamp cap in the opening of the reflector, which
fixing member is adapted to cooperate with the fixing means of the reflector, and
- the connector has main contacts for connecting the discharge lamp to a lamp circuit
when the main contacts of the connector are arranged against the contacts at the lamp
cap,
characterized in that
the connector has additional contacts adapted to be included in a low-voltage circuit
feeding the lamp circuit, while the headlight has beside the lamp cap a contact member
which electrically interconnects the additional contacts of the connector when the
main contacts of the connector are arranged against the contacts at the lamp cap.
2. An assembly as claimed in Claim 1, characterized in that the contact member is
present at the fixing member.
3. An assembly as claimed in Claim 1, characterized in that the contact member is
present at the reflector.
4. An assembly as claimed in Claim 2 or 3, characterized in that the contact member
is electrically conducting and is electrically connected in the circuit by the additional
contacts in series therewith.
5. An assembly as claimed in Claim 4, characterized in that the contact member has
an individual contact part for each additional contact of the connector.
6. An assembly as claimed in Claim 5, characterized in that the additional contacts
are each sunk into an individual cavity in the connector.